Physical-biological control of primary production in Beaufort and Chukchi Sea ice: Its contribution to shelf-basin interactions in the western Arctic

0125464分级器这一跨学科的建议旨在量化在楚科奇和博福特海海冰初级生产。 主要的工作假设是，光和营养供应控制生物量的形成内的海冰。 虽然辐照度控制在春季和秋季的生物量的变化率，营养平流占主导地位，在夏季的融水积累低于冰阻碍营养供应，从而限制了总的生物量积累在冰盖。 为了验证这些假设，该项目结合了实地研究、实验室实验工作和遥感观测。 这种方法的目的是量化与冰有关的生物地球化学过程，并提供一个区域性的，季节性变化的估计碳积累，并从冰盖释放。 船上的工作将在春季和夏季（5月至8月）的两次考察中进行，届时将在包括主要冰型的地点测量物理、化学和生物参数。 冰的厚度和结构将使用间接测量技术沿沿着长度从几百米到几千米不等的断面确定。 将对冰芯进行分析，以确定盐度、温度、稳定同位素浓度、藻类色素浓度和物种组成的垂直分布。 初级生产将使用光学和示踪技术来确定。 实验室实验工作将评估冰的物理学、化学和藻类活动之间的关系，并将实地测量结果外推到早春和夏末，因为那时船上取样比较困难。 遥感数据的综合将有助于对研究区域内冰藻产量及其时空变异性进行区域估计。 该提案有助于实现北极西部陆架-盆地相互作用计划的目标，评估与冰相关的初级生产力的区域贡献以及由此产生的冰向邻近水柱系统的碳积累和释放。 研究结果将有助于理解和量化冰藻群落对气候变化的响应。

0125464GradingerThis interdisciplinary proposal aims to quantify sea ice primary production in the Chukchi and Beaufort seas. The main working hypotheses are that both light and nutrient supply control biomass formation within the sea ice. While irradiance controls the rate of biomass change in spring and autumn, nutrient advection dominates during summer as meltwater accumulation below the ice impedes nutrient supply and hence limits the total biomass accumulation in the ice cover. To verify these hypotheses the project combines field studies, laboratory experimental work and remote sensing observations. This approach is designed to quantify the ice-related biogeochemical processes and to supply a regional, seasonally varying estimate of carbon accumulation in, and release from, the ice cover. The shipboard work will take place during two spring-summer (May-August) expeditions when physical, chemical and biological parameters will be measured at locations encompassing the prevalent ice types. Ice thickness and structure will be determined using an indirect measurement technique along transects varying in length from hundreds to thousands of meters. Ice cores will be analyzed to determine the vertical distributions of salinity, temperature, stable isotope concentrations, algal pigment concentrations and species composition. Primary production will be determined using optical and tracer techniques. Laboratory experimental work will assess the relationships among ice physics, chemistry and algal activity and to extrapolate results of the field measurements to early spring and late summer when shipboard sampling is more difficult. Integration of remote sensing data will contribute to regional estimates of ice algal production and its temporal and spatial variability within the study region. This proposal contributes to the goals of the western Arctic Shelf-Basin Interaction program by assessing the regional contribution of ice-associated primary production and consequent accumulation and release of carbon from the ice to the adjacent water column system. Results are expected to help in understanding and quantifying the ice algal community response to climate variations.